Hydraulic pump



March 31, 1936.

M. E. ERSKINE ET AL 2,035,465

HYDRAULIC PUMP Filed May 21, 1934 M NVENT R S' I wuuMW )uMF/ZM. ATTORNEYS 2 Sheets-Sheet l i atented 7 Mar. 31, 1936 UNITED STATES PATENT OFFICE HYDRAULIC PUMP Wisconsin Application May 21, 1934, Serial no. 726,717 3 Claims. (Cl. 103-136) The invention relates to hydraulic pumps and more particularly to that type of rotary hydraulic pump wherein a rotor revolves around a stationary valve shaft provided with inlet and outlet ports that communicate during the cycle of operations with passages in the rotor which communicate with a plurality of pumping compartments formed between the body of the rotor, vanes in the rotor and a casing.

One of the objects of the invention is to provide a pump of the type above described'in which the pressures acting on the rotor are prevented from shifting the rotor relative to the valve and in which any chance of shearing thev bolts securing the end plates to the rotor body is prevented.

A further object of the, invention is to prevent the pressure on the valve shaft shifting said shaft endwise and exerting "an end thrust upon parts of the rotor.

A further object is to simplify and improve the rotary hydraulic pump shown and described in the patent of P. O. Ott, No. 1,965,388, filed January 9, 1932.

The invention further consists in the several features hereinafter, set forth and more particularly defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is a vertical sectional view through a pump embodying the invention, taken on the line i| of Fig. 2;

Fig. 2 is atransverse sectional view taken on the line 2-2 of Fig. 1. 7

Referring to the drawings, the pump includes a frame or casing formed by the end sections 3 and I and an annular central section 5, these sections being secured together by clampingbolts 6, the end sections having central bores l r in which the outer races of ballbearing journals 8 are mounted.

The rotor includes the main annular or ring shaped body portion 9 and end plates i and I l The end plate l0 has a hubor sleeve portion.

l2 on which the inner race of one of the bearings 8 is mounted and has a drive gear l3 or other suitable member for connecting it with asource of power secured thereto; I

The end plate II has a hub. or sleeve portion H on which the inner race of the other bearing 8 is mounted. r d I The end section 3 has an opening or bore l of smaller diameter than its bore 1 andproviding a shoulder for its bearing and a packing gland I6 is interposed between the bore l5 and the sleeve portion l2.

' portion 20. The passage 24 communicates with a port or recess 21 formed on the outer part of 10 the portion 20 and forming an inlet port while the passage 26 communicates with a port or recess 28 also formed on the outer part of said portion 20 at the opposite side thereof from the recess 21 and forming an outlet port. The ports 21 and 28 are separated from each other by the parts 29 of the portion 20. Beyond these ports atone side, the portion of said shaft has a plurality of radially disposed passages 30 leading from the pressure or outlet conduit 26 to an 2 annular groove 3| on the outer surface of said portion.

The rotor body 9 is provided with a central bore 32,. of -a size-to provide a running fit with the valve portion 20 of the shaft I], and has a 5 series of vane-guiding and carrying slots 33 in p which the vanes or blades 34 are 'slidably mounted and having outer edges engaging the inner surface of the cylinder barrel or ring 35, said blades dividing the space between the rotor and 30 ring into a plurality of pumping compartments 36 and at the base of each slot a passage 31 leads to the annular groove 3| in the shaft H which groove, it has been'noted,'forms a part of the discharge line and thus fluid under pressure is delivered against the backs of the blades at all times and serves to constantly urge them out wardly against the ring 35. These blades are substantially radially disposed or slightly offset from a radial line so that as the rotor revolves 40 the barrel or ring 35 will also rotate. Radially disposed passages 38 are formed in the 'rotor body between adjacent blades and serve to connect each of the pumping compartments with the ports 21 and 28 respectively as the rotor is turned or driven. a

The rotorbody 9 is firmly clamped between the end plates l0 and II by a plurality of radially disposed bolts 39 extending through said parts. imposed on these bolts and also to prevent a lateral movement of the rotor body 9 due to I pumping pressures and consequent wear on one side of the valve the hub portions of said end plates have inwardly extending annular portions .55

To prevent, any shearing action being f 45 and 4| respectively whose inner ends are adapted to have a running fit with the shoulders I I and 22 and whose thickness is equal to the outer diameter of the portion 20 plus a working clearance for the body 3 of the rotor. These ring portions 40 and 4| have a tight fit in the bore 32 of the rotor so that the rotor cannot shift relative thereto and hence the bolts are relieved of all shearing stresses.

To hold the shaft I! in proper angular position it is connected by a key 42 to a plate 43 secured to the end plate 4 by bolts 44 and having an annular bearing retainer portion 45.

To hold the shaft I'l against endwise movement due to discharge pressure the end portion II has a threaded portion 46 mounted in a threaded bore 41 in a plate 48 also secured to the end section 4 by the bolts 44.

The ends it and I9 of the shaft portions l8 and I! are shown as provided with pipe threads to receive the supply and discharge pipes respectively or suitable fittings therefor.

Beyond the periphery of the rotor body 9, the end plates Ill and H form an annular space in which the ring or barrel 35 has a working fit so that it is free to rotate and be shifted laterally thereon. Said ring 35 also has an annular groove 49 formed therein and forms the race of a roller bearing including spaced rollers 50, and the outer race ring 5| which has diametrically disposed fiat faces 52 slidably shiftable upon guide bosses 53 formed on the central section 5.

It will be noted that shifting of the ring 5| will also shift the barrel 35 and will cause it to be shifted off center relative to the rotor, and upon the extent of eccentricity thus produced will depend the volume of pressure fluid delivered by the pump and hence its pumping capacity. Any suitable means may be used to shift the ring or member 5| and in the present instance we have shown a manually operated mechanism in Fig. 1 for this purpose comprising a shaft or rod 54 anchored at one end to the member 5| and connected to move with a rotary sleeve nut 55 by a shoulder 56 engageable with the inwardly extending flange 51 of said nut and held in operative position relative thereto by a retaining nut 58 which permits the nut 55 to rotate freely relative to the rod 54. The threaded end 59 of the nut 51 engages the threaded bore 60 formed in the boss 6| on the midsection 5 of the outer casing. Turning the nut 55 inwardly moves the rod or shaft 54 inwardly and consequently shifts the member 5| and barrel 35 downwardly while turning the nut 55 upwardly moves the shaft 54, member 5|, and barrel 35 upwardly to the position shown in Fig. 1.

With the above construction and assuming clockwise rotation of the rotor as viewed in Fig. 1, while the vanes 34 of the rotor on the side adjacent the port 21 are passing through about half of their revolution the compartments between these blades are gradually enlarged and suction takes place, the fiuid coming from the pipe portion l8 and passing through the passage 24, port 21, and passages 38 into these compartments, these passages 38 being shut off successively as the rotor passes the part 29 at the upper part of the shaft and as the vanes move around on their other half of the cycle the spmes between them and the rotor and ring 35 gradually contract, and the fiuid is then discharged through the passages 33, port 28, passages 26 and to the pressure discharge line at the desired working pressure, it being noted that some of this pressure fluid proceeds from the passage or shaft portion 25 through the passages 30, 3|, and 31 into the slots 33 to constantly act on the backs of the blades 34 to hold them against the ring 35. It is also to be noted that the blades 34 do not revolve relative to the ring 35, but said ring is free to revolve with the blades and with the end plates III and II, the roller bearings 50 offering no appreciable resistance to turning of the ring and the pressure of the blades against said ring being such as to carry the ring with them. Owing to the fact that the ring is, during pumping, eccentrically disposed relative to the axis of the rotor, the blades 34 move in and out and cooperate with the barrel to accomplish the pumping action as described above. Since the travel of the blades in and out relative to the rotor is dependent upon the eccentricity of the ring 35'relative to the rotor, it will be noted that decreasing this eccentricity reduces the volume of liquid handled by the pumping compartments, and finally at zero eccentricity or when the center of revolution of the ring 35 coincides with the axis of the valve shaft I1, no reciprocating movement of the blades takes place and no liquid will be pumped.

As the valve shaft is firmly held in place against endwise movement, there is no end thrust occasioned by the association of this shaft with the rotor, and as the end plates determine the working fit of the body of the rotor relative to the valve portion of the shaft, the seals may be accurately determined and maintained.

It is also to be noted from Fig. 1 that the valve structure is such that only one of the passages 38 can be sealed off by the part 29 between suction and discharge at any one time during the cycle of operation .of the pump, and this is important for the efficient operation of the pump as it prevents the locking oif of a plurality of pumping compartments on the pressure portion of the cycle.

Each of the hubs l2 and I4 have spiral grooves 64 for conducting oil to the parts of said hubs revolving about the fixed shaft l1, said grooves connected by suitable passages with the interior of the outer casing which is filled with oil.

We desire it to be understood that this invention is not to be limited to any particular form or arrangement'of parts except in so far as such limitations are included in the claims.

What we claim as our invention is:

1. In a pump of the character described, the combination with a supporting frame, a valve shaft having a cylindrical valve portion provided with inlet and outlet ports and end portions of smaller diameter than said valve portion provided with inlet and outlet passages respectively communicating with said inlet and outlet ports, a rotor having an annular body portion mounted to rotate about said valve portion and end plates secured to said body portion, said end plates having inwardly extending ring portions abutting said valve portion and mounted to turn on the end portions of said shaft and upon which said body portion is mounted, and journals in said frame for said hub portions, a shiftable ring member revolving with the rotor and defining therewith a chamber, said ring member being slidable between said end plates, reciprocating blades mounted in the body of the rotor and working between said end plates and defining with said rotor and ring member a plurality of pumping compartments, said rotor having passages to establish communication between said pumping compartments and said ports in said shaft as the rotor revolves, and means for shifting said ring member relative to the axis of rotation of the rotor to vary the output of the pump.

2. In a pump of the character described, the combination with a supporting frame, a valve shaft having a cylindrical valve portion provided with inlet and outlet ports and end portions of smaller diameter than said valve portion provided with inlet and outlet passages respectively communicating with said inlet and outlet ports, a plate secured to said frame and to said shaft to hold the latter against endwise movement, a rotor having an annular body portion mounted to rotate about said valve portion and overlapping the same and end plates secured to said body portion, said end plates having inwardly extending ring portions abutting said valve portions and mounted to turn on the end P rtion of said shaft and upon which said body portion is mounted, journals in said frame for said hub portions, a shiftable ring member revolving with the rotor and defining therewith and with said end plates a chamber, reciprocating blades mounted in the body-of the rotor and working between said end plates and defining with said rotor and ring member a plurality of pumping compartments, said rotor having passages to establish communication between said pumping compartments and said ports in said shaft as the rotor revolves, and means forshifting said ring member relative tothe axis of rotation of the rotor to vary the output of the pump.

3. In a pump of the character described, the combination with a supporting frame, a fixed valve shaft having cylindrical valve portion provided with inlet and outlet ports and end portions of smaller diameter than, said valve portion provided with inlet and outlet passages respectively communicating with said inlet and outletpo'rts, a rotor having an annular body portion mounted to rotate about said valve portion and overlapping the same and end plates secured to said body portion, said end plates having inwardly extending ring portions mounted to turn on the 'end portions of said shaft and including inwardestablish communication between said pumping compartments and said ports in said shaft as the rotor revolves, and means for shifting said ring member relative to the axis of rotation of the rotor to vary the output of the pump.

MALCOLM E. ERSKINE. WILLIAM REINHARDT. 

